Improvement in mechanical movements



67, ALEXANDER WALLACE.

Improvement in Mechanical Movements.

Pat.en*ed.lan.2.1872.

gunman Wtmm ALEXANDER WALLACE, OF JACKSONVILLE, ASSIGNOR OF ONE-HALF HIS RIGHT TO LEONARD R. TURNER, OF FERNANDINA, FLORIDA.

IMPROVEMENT IN MECHANICAL MOVEMENTS.

Specification forming part of Letters Patent No. 122,502, dated January 2, 1872.

Specification describing certain Improvements in Mechanical Movement invented by ALEXANDER WALLAoE, of Jacksonville, in

the county of Duval and State of Florida.

The object of the invention is to avoid deadcenters in the crank movement by which a reciprocating motion is secured from motive powers.

Figure l is a plan, and Fig. 2 a section, showing the radial planes, in which are, respectively, the crank-pin and the crank-arm.

A is the balance-wheel, provided with crankpin a and shaft a having crank-arm (0 B is the crank-pitman, and C the slide or gate which it reciprocates. D is the frame which supports the mechanism. The axis of the crank-wheel is arranged in a horizontal plane, nearly or quite as much above the plane in which the slide moves as is the distance between the said axis and the crank-pin a. By this construction I cause the pitman to move nearly in a straight, and on the shortest possible line, when moving forward against the resistance of the work to be done, while it travels on a large curve or are When returning and meeting with no resistance. be passed through the shaft a and arm (6 and another through crank-pin a and shaft a it will be perceived that a diedral angle is formed and that the crank-arm a is thus placed in advance of the crank-pin a. i

If one plane By this construction the steam is cut off from the piston after the slide has reached its maximum throw, both on the forward and backward stroke, which causes the steam to take the pitman over its dead-centers on each side, while during the interval between the shutting off of steam on one side of the piston and entering it on the other the balance-wheel has acquired momentum enough to carry the crankarm a over each of its dead-centers.

Having thus described all that is necessary to a full understanding of my invention, What I esteem to be new, and desire to secure by Letters Patent, is

1. The balance-wheel having its axial shaft to arranged nearly or as far above the plane of movement of the reciprocated slide C as the distance between said axial shaft a and the crank-pin to as and for the purpose set forth.

2. The balance-wheel A provided with crankarm a, arranged in advance of its crank-pin a as and for the purpose described.

3. The shaft (0, crank-pin a and crank-arm a of a balance-wheel, A, arranged With respect to the pitman B and slide or gate 0, as and for the purpose described.

ALEXANDER WALLACE. 

